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How important is the efficiency of a speaker to you?

I went to an audio meeting recently and heard a couple of good sounding speakers. These speakers were not inexpensive and were well built. Problem is that they also require a very large ss amp upstream to drive them. Something that can push a lot of current, which pretty much rules out most low-mid ( maybe even high) powered tube amps. When I mentioned this to the person doing the demo, i was basically belittled, as he felt that the efficiency of a speaker is pretty much irrelevant ( well he would, as he is trying to sell these speakers). The speaker line is fairly well known to drop down to a very low impedance level in the bass regions. This requires an amp that is going to be $$$, as it has to not be bothered by the lowest impedances.

Personally, if I cannot make a speaker work with most tube amps on the market, or am forced to dig deeply into the pocketbook to own a huge ss amp upstream, this is a MAJOR negative to me with regards to the speaker in question ( whichever speaker that may be). So much so, that I will not entertain this design, regardless of SQ.

Your thoughts?

daveyf

Showing 4 responses by herman

herman
2,280 posts
 

The amplifier takes time to make this power (i.e., slew rate). So the amp "slews" 3.16 times faster to reach the same volume level resulting in increased dynamics for the high efficiency speaker.

that's not how it works, that is not how slew rate factors into how an amplifier works. Slew rate is directly related to bandwidth, not how quickly it reaches peak power operating within it's specified bandwidth. 

 an amp operating withing it's specifications that is  producing  100 W RMS at a given frequency will reach peak power in  the same amount of time as a 1 W RMS amp will.

Example.... at 1000 Hz the period is .001 seconds. So starting at zero crossing  it reaches a peak  .00025 sec later , crosses zero in the opposite direction at .0005 sec, the opposite peak at .00075 sec, and back to zero at .001... no matter how much power it is producing..  If it didn't it would be distorting the signal. 

 

herman
2,280 posts
 

"an amp operating withing it’s specifications that is producing 100 W RMS at a given frequency will reach peak power in the same amount of time as a 1 W RMS amp will."

 

You missed the point. I said ALL OTHER THINGS BEING EQUAL. So the same amp, be it 1 watt or 100 watts, is used with both speakers.

Obviously a 100 watt amp will produce 1 watt (0.278 times the voltage) quicker than it will produce the full 100 watts.

I’m sorry, but your understanding of slew rate and how it applies to how an amp operates is simply incorrect. Slew rate describes how fast an amplifier is capable of changing, not how fast it is changing. It describes the maximum rate of change, not how how fast it is changing for a given input

The point is, slew rate has absolutely nothing to do with efficiency or how dynamic a speaker is or anything being discussed here. Your concept of slew rate is wrong. Sorry if you don’t get that.

 

@herman Would that be in Denver or NYC?

I have absolutely no idea what you are talking about

herman
2,280 posts
 

https://www.audioholics.com/audio-amplifier/amplifier-slew-rate

 

herman
2,280 posts
 

If you look into this a bit further you will discover that these other waves are combinations of sine waves, and there are no musical signals which have an instantaneous rise time. If you put any musical signal through a spectrum analyzer you will see it broken down into these various frequencies.

https://mathworld.wolfram.com/FourierSeries.html

As the article you dismiss states, once the slew rate of the amplifier is high enough that it can amplify the highest required frequencies without distorting them (it is not slew rate limited) then a higher slew rate does not matter.

I’ll leave it to you to dig in and educate yourself about this, since instead of trying to understand slew rate, it appears you are only interested in proving you were right despite the fact what you initially stated is undeniably incorrect.

I’m done with it. Good luck in your journey.

 

 

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